Tri-(fluoralkyl phenyl) phosphates and method for producing them



United States Patent TRI-(FLUDRALKYL PHENYL) PHOSPHATES AND METHOD FOR PRODUCING THEM Douglas H. Moreton, Pacific Palisades, and Bertram Keiliin, Eianta Monica, Caliii, assignors to Douglas Airraft Company, Inc Santa Moni a, Calif- No Drawing. Application February 20, 1950, Serial No. 145,311

16 Claims. c1, 260-461) This invention relates to certain tri-(fluoralkyl phenyl) phosphates and to a method for producing them.

We have discovered that certain tri-(trifluoralkyl phenyl)phosphates can not only be made in accordance with the process of our invention but also that these chemical compounds have surprising and advantageous properties. (fluoralkyl phenyl) phosphates in which the end carbon atom of the alkyl group has three fluorine atoms and the alkyl group from one to four carbon atoms in the m-, or ppositions. These compositions have a combination of properties making them useful to a surprising degree as fire resistant or relatively non-flammable heat transfer fluids, functional fluids or lubricants. The tri-(trifluoralkyl phenyl) phosphates of my invention particularly include tri-(m-trifluormethyl phenyl) phosphate and tri-(meta-2,2,2-trifluorethyl phenyl) phosphate.

The following specific example relating to tri-(m-trifluormethyl phenyl) phosphate will illustrate and exemplify our invention.

Example 161 grams of meta-trifluormethyl aniline was reached with 70 grams of sodium nitrite in the presence of 220 ml. of concentrated sulfuric acid at about 05 C. to effect diazotization and produce meta-trifluormethyl phenyl diazonium sulfate as indicated by the following equation:

The solution containing the meta-trifluormethyl phenyl diazonium sulfate was heated with boiling water and sulphuric acid to drive oh? nitrogen and replace the diazo group with a hydroxyl group as indicated by the followmg:

200 grams of the liquid meta-trifluormethyl phenol was then reacted with phosphorus oxy-chloride (POCls) by stirring for two hours at room temperature and for 36 hours at 100 C. until evolution ofHCl gas had ceased. This process produced the desired new chemical compound tri-(meta-trifluoralkyl phenyl) phosphate as indicated by the following equation:

The resulting product was then cooled and poured into one liter of NaOH solution to neutralize any residual acid and also to separate out any unreacted trifluormethyl phenol, which is soluble in the sodium hydroxide solution. Moreover, the sodium hydroxide solution also separates out any monoor disubstituted ester. This was shaken well and the oily layer separated out and washed twice with 100 ml. portions of 10% NaOH solution and then with distilled water until washings were neutral to litmus paper. The oily ester was then dissolved in benzene, decolorized with charcoal and dried over calcium chloride for hours. It was then filtered and the benzene distilled under reduced pressure. This gave 98 grams of a light brown oily liquid which could not be distilled without decomposition under a reduced pressure as low as 14 mm. of Hg.

8 This new oily ester, tri-(m-trifluormethyl phenyl) These phosphates particularly include the triice phosphate, was found to have the following physical properties:

Specific gravity 60/60 F. 1.458

Pour point .35 F. (supercooled) Melting point +35 F. Viscosity at F. 13.17 centistokes Viscosity at 210 F. 2.55 centistokes Autogenous ignition temperature (glass) above 1100 F.

(m-tri-fluormethyl phenyl) phosphate may be made by reacting the meta-trifluormethyl phenol directly with the POCls as described above. Furthermore, in general, any of the tri-(trifluoralkyl phenyl) phosphates of our invention may be so made. This particularly includes the following such phosphates:

Tri-(ortho-trifluormethyl phenyl) phosphate Tri-(meta-trifluormethyl phenyl) phosphate Tri-(para-trifiuormethyl phenyl) phosphate Tri-(ortho-2,2,2-trifluorethyl phenyl) phosphate Tri-(meta-2,2,2-trifiuorethyl phenyl) phosphate Tri-(para-2,2,2-trifluorethyl phenyl) phosphate Tri-(ortho-3,3,3-trifiuorpropyl phenyl) phosphate Tri-(meta-3,3,3-trifluorpropyl phenyl) phosphate Tri-(para-3,3,3-trifluorpropyl phenyl) phosphate Tri-(ortho-4,4,4-trifluorbutyl phenyl) phosphate Tri-(meta-4,4,4-trifluorbutyl phenyl) phosphate Tri-(para-4,4,4-trifluorbutyl phenyl) phosphate The above description and examples are intended to be illustrative only and not to limit the scope of the invention, and our invention extends to all modifications and variations which fall within the spirit and scope of the appended claims.

We claim:

1. A tri-(trifluoralkyl phenyl) phosphate in which the alkyl group has from one to four carbon atoms and the fluorine atoms are on the end carbon atom of the alkyl group.

. A tri-(trifluorrnethyl phenyl) phosphate.

Tri-(ortho-trifluormethyl phenyl) phosphate.

. Tri-(meta-trifluormethyl phenyl) phosphate.

. Tri-(para-trifiuormethyl phenyl) phosphate.

A tri-(2.2,2-trifluorethyl phenyl) phosphate.

. Tri-(ortho-2.2 2-trifiuorethyl phenyl) phosphate.

. Tri-(meta-2,2,2-trifluorethyl phenyl) phosphate.

The process of producing a tri-(trifluoralkvl phenyl) phosphate which comprisesv diazotizing a tri-fiuoralkyl aniline to a tri-fluoralkyl phenyl diazonium salt, hydrolizing said fiuorinated diazonium salt to the corresponding fiuorinated phenolic compound, and reacting said phenolic compound with phosphorus oxychloride to produce the tri-(trifluoralkyl phenyl) phosphate.

10. The process of producing a tri-(trifiuoralkyl phenyl) phosphate which comprises reacting a trifluoralkyl phenol with phosphorus oxychloride to produce the tri- (trifluoralkyl phenyl) phosphate.

11. A process as defined in claim 9 in which the resulting product is washed with sodium hydroxide solution to neutralize residual acid, separate out unreacted fluorinated phenolic compound and monoand disubstituted fiuorinated esters, and then the oily fiuorinated ester liayeg is separated, dissolved in benzene, decolorized and 12. A process as defined in claim 10 in which the resulting product is washed with sodium hydroxide solution to neutralize residual acid, separate out unreacted 0 fiuorinated phenolic compound and monoand disub- Patented Nov. 9, 1954 ester layer is separated, dissolved in benzene, decolorized and dried.

13. The process of producing tri-(meta-trifiuormethyl phenyl) phosphate which comprises reacting meta-trifiuormethyl phenol with phosphorus oxychloride to produce tri-(meta-trifluormethyl phenyl) phosphate.

14. The process of producing a tri-trifluormethyl phenyl) phosphate which comprises reacting a trifiuormethyl phenol with phosphorus oxychloride to produce a tri- (trifluormethyl phenyl) phosphate.

15. The process of producing tri-(meta-2,2,2-trifiuorethyl phenyl) phosphate which comprises reacting a meta- 2,2,2-trifluorethy1 phenol with phosphorus oxychloride to produce tri-(meta-2,2,2-trifiuorethyl phenyl) phosphate.

16. The process of producing a tri-(2,2,2-trifluorethy1 phenyl) phosphate which comprises reacting a 2,2,2-trifiuorethyl phenol with phosphorus oxychloride to produce the tri-(2,2,2-trifluorethyl phenyl) phosphate.

References Cited in the file of this patent UNITED STATES PATENTS Name Number D Midgiey et a1 Aug.

Number Name Date 2,217,706 Reid Oct. 15. 1940 2,330,251 Taylor Sept. 28, 1943 2,340,331 Knutson et a1 Feb. 1, 1944 2,358,133 Stoesser Sept. 12, 1944 2,373,807 Beeg Apr. 17, 1945 2,395,380 Morgan Feb. 19, 1946 2,566,623 Moreton Sept. 4, 1951 2,574,516 Walter Nov. 13, 1951 FOREIGN PATENTS Number Country Date 3,053 Great Britain of 1914 455,014 Great Britain Oct. 12, 1936 OTHER REFERENCES Chemical Abstracts, vol. 38, col. 1483 (1944) citing Brensch, Rev. faculte sci. univ. Istanbul 7A, 182-9 (1942) (in German).

Gilman, Organic Chemistry, vol. I (2d ed.1946), pages 950-951. 

1. A TRI-(TRIFLUORALKYL PHENYL) PHOSPHATE IN WHICH THE ALKYL GROUP HAS FROM ONE TO FOUR CARBON ATOMS AND THE FLUORINE ATOMS ARE ON THE END CARBON ATOM OF THE ALKYL GROUP.
 9. THE PROCESS FOR PRODUCING A TRI-(TRIFLUORALKYL PHENYL) PHOSPHATE WHICH COMPRISES DIAZOTIZING A TRI-FLUORALKYL ANILINE TO A TRI-FLUORALKYL PHENYL DIAZONIUM SALT, HYDROLIZING SAID FLUORINATED DIAZONIUM SALT TO THE CORRESPONDING FLUORINATED PHENOLIC COMPOUND, AND REACTING SAID PHENOLIC COMPOUND WITH PHOSPHOROUS OXYCHLORIDE TO PRODUCE THE TRI-(TRIFLUORALKYL PHENYL) PHOSPHATE. 